Common TCP/IP Protocols

Question 1

Protocol

Answer 1

A set of standards for communication between network hosts

Question 2

Protocol suite

Answer 2

A group of protocols intended to be used together

Question 3

Name Web services protocols

Answer 3

• Hypertext Transfer Protocol (HTTP)

* HTTP over SSL (HTTPS)

Question 4

Hypertext Transfer Protocol (HTTP)

Answer 4

• Is used by web browsers and web servers o exchange files (such as web pages) through the World Wide Web and intranets.
• Can be described as an information requesting and responding protocol.
• Is typically used to request and send web documents, but is also used as the protocol for communication between agents using different TCP/IP protocols

Question 5

HTTP over SSL (HTTPS)

Answer 5

Is a secure form of HTTP that uses SSL to encrypt data before it is transmitted

Question 6

Name Security protocols

Answer 6

• Secure Sockets Layer (SSL)

* Transport Layer Security (TLS)

Question 7

Secure Layer Security (SSL)

Answer 7

• Secures messages being transmitted on the Internet
• Uses RSA for authentication and encryption
• Web browsers use SSL to ensure safe web transactions

Question 8

Transport Layer Security (TLS)

Answer 8

• Ensure the messages being transmitted on the Internet are private and tamper proof.
• TLS is implemented in two protocols
• TLS Record provides connection security with encryption (with DES for example)
• TLS Handshake provides mutual authentication and choice of encryption method

Question 9

Name the file transfer protocols

Answer 9

• File Transfer Protocol (FTP)
• Trivial File Transfer Protocol (TFTP)
• Secure File Transfer Protocol (SFTP)
• Secure Copy (SCP)

Question 10

File Transfer Protocol (FTP)

Answer 10

• Generic method of transferring files
• Protect access to files by requiring usernames and passwords, and allows file transfer between dissimilar computer systems
• Can transfer both binary and text files including HTML to another host
• *** FTP does not use encryption. All data are sent over the network in clear text **

Question 11

Trivial File Transfer Protocol (TFTP)

Answer 11

• Does not provide user authentication or error detection
• Used when files need to be transferred between systems quickly
• Since it does not perform error detection TFTP is faster than FTP but is susceptible to transmission errors

Question 12

Secure File Transfer Protocol (SFTP)

Answer 12

• Uses SSH to secure data transfer

* SSH ensures that SFTP transmission use encrypted commands and data

Question 13

Secure Copy (SCP)

Answer 13

• Used to securely transfer files between systems

Question 14

Name Email Protocols

Answer 14

• Simple Mail Transfer Protocol (SMTP)
• Post Office Protocol 3 (POP3)
• Internet Message Access Protocol version4 (IMAP4)

Question 15

Simple Mail Transfer (SMTP)

Answer 15

• Is used to route electronic mail through the internetwork
• Is used between mail severs for sending and relaying mail
• Is used by all email clients to send mail
• by some email client programs, such as Outlook for receiving mail from an Exchange server

Question 16

Post Office Protocol 3 (POP3)

Answer 16

• Is used to retrieve email from a remote server and download it to a local client over TCP/IP connection
• *** An email client that uses POP3 for receiving mail uses SMTP for sending mail **

Question 17

Internet Message Access Protocol version4 (IMAP4)

Answer 17

• Designed to enable users to access their mail for various locations, with out the need to transfer messages or files back and forth between computers
• Messages remain on the remote mail server and are not automatically downloaded to a client system
• *** An email client that uses IMAP4 for receiving mail uses SMTP for sending mail **

Question 18

Network Services Protocols

Answer 18

• Dynamic Host Configuration Protocol (DHCP)
• Domain Name System (DNS)
• Network Time Protocol (NTP)
• Lightweight Directory Access Protocol (LDAP)

Question 19

Dynamic Host Configuration Protocol (DHCP)

Answer 19

• Is used to automatically assign addresses and other configuration parameters to network hosts
• Using a DHCP server, hosts receive configuration information at startup, reducing the amount of manual configuration required on each host

Question 20

Domain Name System (DNS)

Answer 20

• A distributed system throughout the internetwork that provides addresses and name resolution
• EX www.mydomain.com would be mapped to a specific IP address

Question 21

Network Time Protocol (NTP)

Answer 21

• Used to communicate time synchronization information between systems on a network

Question 22

Lightweight Directory Access Protocol (LDAP)

Answer 22

• Used to search, retrieve data from, and update a directory service
• This protocol follows a client/server model.
• One or more LDAP servers contain the directory data
• The client connects to an LDAP Server to make a directory service request

Question 23

Network Management Protocols

Answer 23

• Simple Network Management Protocol (SNMP)
• Remote Terminal Emulation (Telnet)
• Secure Shell (SSL)

Question 24

Simple Network Management Protocol (SNMP)

Answer 24

• Designed for managing complex networks
• Lets network hosts exchange configuration and status information.
• This information can be gathered by management software and is used to monitor and manage the network

Question 25

Remote Terminal Emulation (Telnet)

Answer 25

* Allows a computer to remotely access the console of a computer system somewhere else in the network * Was used for remote management task but rarely used today * Does not use encryption - recommended to use a secure alternative to Telnet for remote management task, such as SSH

Question 26

Secure Shell (SSH)

Answer 26

* Allows for secure interactive control of remote systems * Uses RSA public key cryptography for both connection and authentication * Uses the IDEA algorithm for encryption by default, but is can use Blowfish and DES * Is a secure and preferred alternative to Telnet

Question 27

Transport Protocols

Answer 27

* Transmission Control Protocol (TCP) | * User Datagram Protocol (UDP)

Question 28

Transmission Control Protocol (TCP)

Answer 28

* Provides services that ensure accurate and timely delivery of network communication between two hosts * Sequencing of data packets * Flow control * Error checking * Acknowledgement of packets sent * Retransmission of lost packets

Question 29

User Datagram Protocol (UDP)

Answer 29

* Host to host protocol like TCP but * Doesn't acknowledge each packet transmitted * Doesn't allow for retransmission of lost packets * That reduces overhead allowing for faster communications * Ideal of streaming audio and video * Speed come at the expense of possible errors or data loss

Question 30

Control Protocols

Answer 30

* Internet Control Message Protocol (ICMP) | * Internet Group Membership Protocol (IGMP)

Question 31

Internet Control Message Protocol (ICMP)

Answer 31

* Works closely with IP to prevent errors and control information by allowing host to exchange packet status information * Ping and traceroute use ICMP message to check network connectivity * ICMP also works with IP to send notices * When destinations are unreachable * Which route and hops a packets takes through a network * Whether devices can communicate across the network

Question 32

Internet Group Membership Protocol (IGMP)

Answer 32

* Defines host groups * All group members can receive broadcast messages (multicasts) intended for the group * Multicast groups can be composed of devices within the same network or across networks (connected with a router)